9th January 2024

Constipation

• Pain
• Nausea and vomiting
• Faecal retention which can cause rectal distention and impair sensory and motor function of the rectum
• Faecal impaction
• Bowel obstruction
• Faecal incontinence
• Rectal bleeding or prolapse
• Urinary retention and infection
• Agitation
• Delirium

Management of Constipation

Treatment aims to facilitate comfortable bowel movements, not to achieve a particular frequency. Prevention is key, so patients should be asked about bowel habit and encouraged to stay hydrated, eat foods high in fibre like fruit, vegetables, and whole grains, and to keep active. This can be challenging in palliative patients who are approaching end-of-life as their appetites and mobility will often decline.

Patients should be toileted regularly if mobility is reduced, ensuring adequate privacy.

When assessing somebody with constipation, abdominal and rectal examinations should be done to exclude haemorrhoids, fissures and impacted stool in the rectum.

If starting a patient on the medications listed above, especially opioids, consider a concomitant laxative.

Pharmacological:

Laxatives may be divided based on their mode of action:

• Osmotic laxatives include Laxido, Lactulose, Sodium phosphate and Polyethylene glycol
• Stimulant laxatives include Senna and Bisacodyl
• Bulk-forming laxatives include Ispaghula husk and Methylcellulose
• Faecal softeners and lubricants such as Docusate sodium, arachis oil and glycerol which are often given rectally as suppositories. There is often significant overlap between these categories.

Osmotic and bulk-forming laxatives may be of limited value in palliative patients. Lactulose needs to be taken with large volumes of fluid, which may not be possible in these patients, and bulk-forming laxatives may worsen constipation if not taken with adequate fluid.

Stimulant laxatives should be avoided in those with bowel obstruction

Faecal impaction must be treated initially, and this may require rectal treatment.

Manual evacuation may be required, but this should not be attempted without analgesia and sedation.